/Engine/Source/Editor/DataLayerEditor/Public/DataLayer/DataLayerEditorSubsystem.h
Gets all known DataLayers and appends them to the provided array
void AddAllDataLayersTo ( [TArray](API\Runtime\Core\Containers\TArray)< [TWeakObjectPtr](API\Runtime\Core\UObject\TWeakObjectPtr)< [UDataLayerInstance](API\Runtime\Engine\WorldPartition\DataLayer\UDataLayerInstance) >> & OutDataLayers ) const